I'm not sure why "Go Investigation", Diplomacy has all the blue and purple medical supplies you need for the skill. I have two biochems on one server, so I have one who has Diplomacy and supplies the two of them, the other was free to take Slicing for the cred, missions, and to support a cybertech alt.

Nice start to the guide. If you're willing to compile it, I think it would be great to have specific examples of what sells and what doesn't. For instance, the mods mentioned above are usually hot sellers as are enhancements from artifice and blue medpacks/stims from bio chem. Although I'd challenge your statement about Biochem being under represented. If it's anything like my server, people are switching to it at endgame (because of the reasons stated all over this forum) and have the credits to buy up inventory from the GTN. My server has hardly any bio materials in the GTN, and they get swooped up in a heartbeat when they are placed. In general, though, I'd caution against the gathering and selling method of cash generation. The game is still to early to have the vast amount of free money at endgame that cause folks to want to spend off the GTN versus getting it themselves. This is heightened by the fact that any person can pick up the required support skills meaning you are only selling to either the people who don't want the required gathering skill, or who needs just a few items to level out of their bracket. Right now, the market for either is slim (but not nonexistent). I'll also give you a little tidbit I haven't seen posted in this thread. There are quite a few people in this game who don't realize that Nar Shaddaa is a neutral GTN and not linked to the faction GTN. Mission skills often times drop unusable schematics for your faction. I've made quite a bit of money so far buying up orange schematics that are Imperial only (for instance, a synthweaving schematic for Sith Inq) on the Republic GTN for usually between 200-300 credits, and sell it on the Neutral for 1500-2000 (or more for higher level oranges). But really, this boils down to any way of making money, you need to know your market, and you need to be a little lucky with the timing.

This one is a pretty good solution, however you'd have to cap it by world. For instance, I'd hate to allow 50s to loot Dromunc Kaas/Coruscant chests for level appropriate gear. But I like the solution.

As a slicer pre nerf, I found plenty of slicing nodes questing through Dromund Kaas through Alderaan (L26 BH). I haven't looked since the nerf, but I would bet that most of the slicers pre-nerf were spending most of their time running missions and skipping the relatively low rewards on nodes. Now since the missions aren't lucrative, they are all competing for those same nodes.

Actually, with my latest Biochem I had Corso crit purple on a diplomacy mission the first time I used it. Level 11, Diplomacy 1, moderate light side diplomacy mission brought back 2 biochemical bonding agent and 2 alien blood. So, it might be rarer with Moderate yield, but it can happen.